My above referenced co-pending patent application discloses an autonomous, personal service, robotic apparatus that is particularly useful as a golf caddy apparatus. The robotic apparatus comprises a drive assembly, for propelling the robotic apparatus, and onboard electronics, including a digital computer and a memory device, which store map data of a golf course or other environment in which the robotic apparatus is to move, and navigational rules for controllably steering the robotic apparatus through the environment. A position or location determination assembly is part of the onboard electronics and functions to determine the location of the robotic apparatus in the environment. The position determination assembly works in conjunction with a differential GPS system to locate the robotic apparatus to within a relatively small error envelope or bubble, for example, within one cubic meter. The robotic apparatus further includes sensing apparatus that dynamically sense unmapped obstacles in the immediate vicinity of the robotic apparatus, to avoid collision therewith. The robotic apparatus also includes apparatus for sensing the location of a person, such as a golfer, or a second robotic apparatus, in the environment, and the stored navigational rules provide operational criteria for guiding the robotic apparatus relative to such person or other robotic apparatus.
The present invention improves upon the robotic apparatus of my forementioned patent application by providing an improved guidance system for steering the robotic apparatus, particularly when communication with a sufficient minimum number of satellites is temporarily lost.